The modern life is flooded with all kinds of digital information since the electrical industry has rapidly developed. Data transmission, which is applied at a mobile communication, personal computer, digital appliances, and network communication, is handled by digital process, and the clock signal is generated to trigger for that, for example, the clock signal can be generated to coordinated the data signal between each chip and the system within the personal computer in order to deal with digital data transmission and application.
Recently, there are many different clock signals within a system as a result of each element having different advance and operation frequency; for example, the main clock frequency of the motherboard is 133 MHz, and that of the Central Process Unit (CPU) is 1.3 GHz, etc. Therefore, the clock synchronization and regulation between different operation frequencies of the elements will be very important within the system in order to transmit the data correctly therewith.
However, when a clock signal between each of chips or elements is regulated according to the reference clock signal, it is easy to offset the reference clock signal according to the differential distance therefore. Thus, the clock signal will be regulated difficulty, and further causes the system suspense. Consequently, the stability within the system operation is determined by how to adjust the offset of the clock signal between different operation frequencies of elements.
The offset of the clock signal is regulated manually in the prior art, that is, the user must adjust the resistors and the capacitors placed at the external of the clock generator in accordance with the motherboard layout. For example, for the purpose of clock synchronization between each of chips or elements in a motherboard, smaller resistors and capacitors of the element are implemented if the distance between elements is long, and on the other hand, larger resistors and capacitors of the element are implemented if the distance between elements is short. However, it is hard to realize how the offset of the clock signal is with the traditional method, and it is not accurate enough to control the offset range of the clock signal between each of chips or elements with just the initialization to the clock signal. Meanwhile, the motherboard design is more complex and it is inconvenient for an end user to use the motherboard.